Flour Beetle Description

Flour Beetles, or “bran bugs,” only grow to approximately 1/8 of an inch long. Their bodies are flat and elongated and are a shiny reddish-brown in color. While they do have the ability to chew, they do not sting or bite.

Flour beetles have two small antennae, and the appearance of the antennae is one of the main ways to distinguish the type of Flour Beetle you are dealing with. Flour Beetles have small wings and while the red flour beetle can fly, the confused flour beetle cannot. This important difference makes the red flour beetle much more capable of widespread infestation.

Flour Beetles go through a complete metamorphosis, just like a fly or a flea and lay tiny eggs that are clear to white in color. These eggs hatch into tiny creamy colored - brownish white larvae. Once the larvae are mature and developed,, they will take on a yellowish tint and are about 3/16 of an inch long. The larvae then goes through a transformation phase and becomes a pupae. The pupae is actually a soft shell inside which the matured larvae develops and fully matures into a fully grown adult beetle capable of reproduction and widespread infestations.

Types of Flour Beetles - Red and Confused Flour Beetles

There are two types of Flour Beetles – the Confused Flour Beetle and the Red Flour Beetle. Both of these Flour Beetles have unique physical characteristics and qualities. They are also found in different areas.

Red Flour Beetles

Red Flour Beetlesor Tribolium castaneum, are believed to have Indo-Australian roots and prefer temperate areas, but can survive colder temperatures as well. In the United States, they are the most prominent in the Southern states. Also unlike Confused Flour Beetles, the Red Flour Beetle has the ability to fly. Their antennae consist of only three segments, and the tip is much longer than the previous segments. Also worth noting is that the Red Flour Beetle’s thorax is curved while the Confused Flour Beetle’s thorax is straight.

Confused Flour Beetles

Confused Flour Beetles or Tribolium confusum, are have been distributed all over the world, but prefer coolor temperatures. This makes them more prominent in the Northern United States. It is believed that the Confused Flour Beetles originated in Africa. Confused Flour Beetles are not able to fly and their antennae have segments that grow from base all the way to the tip, gradually. Because their antennae grow gradually from the “bottom up” their clubbed antennae consist of four segments.

Adult Red and Confused Flour Beetles.(Actual Size - 1/8 inch). The Red Flour beetles are lighter in color and will sometimes fly. The Confused Flour Beetle is darker in color and will not fly.

Flour Beetle Facts

Flour Beetles get their name because they most commonly infest flour and other grains. While Flour Beetles aren’t able to eat whole grains, they do feed on dockage, fines and grain dust. Unlike many other insects, Flour Beetles mate and lay their eggs in the food they are contaminating. The female Flour Beetle has the ability to lay up to 450 eggs. She will lay her eggs on broken kernels or other loose food materials.

It only takes Flour Beetle eggs 5-12 days to hatch. Once they hatch, they will immediately begin to feed and grow into larvae. It only takes the Flour Beetle four months to reach adulthood once hatched. Adult Flour Beetles generally only live for about a year, but have been known to live up to 3 years in some areas.

Flour Beetles are more of a nuisance than a damage-causing pest. They will not feed on or destroy furniture like many household pests. If they are discovered in grains or food products, the products will have to be tossed out. For livestock owners, Flour Beetles can be a problem because they enjoy feeding on the grains used to feed these animals and the animals will refuse to eat it if Flour Beetles are present. It also diminishes the value of the feed if they are found within it.

Foods That Flour Beetles Infest

Flour Beetles prefer to feed on grain products, however, they will eat a wide variety of foods, if nearby. This is why Flour Beetles are such a problem for homeowners. They don’t just contaminate a bag of flour and that’s it. They have been found in the following food products, as well: dried fruits, sunflower seeds, cornmeal, crackers, cereals, nutmeats, rice, wheat, oats, wheat bran, beans, chocolate, legume seeds, vetch seeds, powdered milk, spices, pet food, livestock feed, birdseed, cottonseed, dried flowers and even poisonous baits.

Red and confused flour beetles can infest practically any kind of dried grain, food product or powder. This is why inspection for these beetles needs to be extensive and every single food product of this nature needs to be thorough evaluated and if a determination is made that flour beetles exist, then thrown away immediately. It is never a good idea to try and salvage food by freezing or sifting to remove the insects. Any food that has evidence of flour beetles is considered contaminated and simply removing the beetles will not remove the contamination.

How to Get Rid of Red and Confused Flour Beetles

If you find Flour Beetles early enough, then you won’t need to resort to insecticides to eliminate the problem. Removing the contaminated product by sealing it in an airtight bag or container will take care of the issue. However, if the Flour Beetles have been found in more than one or two food sources, or have been there for a while, you’ll need to proceed with a flour beetle inspection and control program. Simply placing traps or spraying for these pesky beetles will not result in any kind of control.

If you find flour beetles in your home then here is what you need to do:

Inspect all food products stored in your pantry or food storage area. Every single product that contains flour, especially bread flour and whole wheat flour (the worst) should be inspected. Also, cake mixes, corn meal, cereals, spices, dry dog food, bird food and bird seed, ANYTHING that is a dry grain based product must be inspected. Open the container and pour the contents into a large bowl and inspect for beetles. If you find any evidence of beetles, throw that product away immediately, and if recently purchased, take it back to the store and get your money back.

Completely empty the pantry or food storage area, the vacuum and clean like crazy! Make sure that there are no food crumbs anywhere and that the entire area is spic and span.

Replace any old or worn shelf liners with NON-STICK shelf liner. Do not use newspaper or paper period. Always use something you can wipe down with a wet towel and clean. Sticky shelf liners are are perfect food source for many pests including cockroaches.

Spray the cracks and shelf corners with an insecticide such as Demon WP, Demand or Gentrol Aerosol. Products such as Ultracide, while labeled primarily for fleas will do an excellent job of killing flour beetles and also provide the insect growth regulator that keeps the immature beetles from developing.

After the shelves have dried, replace all food items. Make sure that you have thoroughly inspected all foods, bags, boxes, etc. The only thing you don't have to inspect are canned goods.

Red and Confused Flour Beetle Prevention Tips

To prevent flour beetles from infesting your pantry or home you should do the following:

Never buy whole grains, cereal, cake mixes, flour, bread flour, spice bags, dry dog food, bird seed, etc, without first inspecting for tiny holes in the bags and or boxes. Tiny holes in the bags or box could indicate the presence of flour beetles inside the bag.

ANY infested product you find at home should be thrown away immediately. Do not try to FREEZE or kill the flour beetles inside the box. Freezing for a period of 24-48 hours will kill the adult beetles, but may not affect the larvae. Also, no one wants to eat dead flour beetles in their food!

Place all grains, dog foods, cake mixes, spices etc. that come in a paper bag or box inside a sealed plastic bag, or better yet, empty the contents into an air-tight plastic container with a tight fitting lid.

Keep the pantry and food storage areas clean, dry and crumb free. Vacuum and sweep the shelves just as you would any other surface in your home. Pay attention to the cracks along the sides of the shelves where food crumbs may collect. The presence of food crumbs not only helps flour beetles to live and multiply but also cockroaches, and other insects.